Master planning priority assignment involves matching up the supply of a product to the demands for the product. This becomes particularly important when there is not enough supply to meet the demand. One of the tasks of a priority assignment planner is to determine which customer demands take priority and which demands have the possibility of not being met in the time frame requested. In a small organization it may be possible to perform this prioritization by reviewing each demand entry and making a determination of its priority compared to all other demands. An automated method to perform this prioritization is required once the number of demands or products becomes large. Systems currently exist which allow a priority assignment planner to automate the prioritization process and to use the computer to assign priorities to demands. In many cases it is possible to group customers or demand time frames into general categories in terms of prioritization. For example, it may be the rule in a particular organization that all demand time frames of 3 months from the start of the planning horizon get a priority of “4.” This grouping of like attributes is advantageous because it saves the priority assignment planner time. However, in most cases there will also be exceptions to the general rules and the priority assignment planner must take them into account when assigning priorities to specific demands. Current master planning priority assignment systems do not offer the functionality to specify general business rules for priority assignment and then the ability to specify exceptions to the general business rules. Instead of general business rules, current master planning priority assignment systems require priorities as input.